Need help answering a question about selling a property and not paying capital gains

[David Lant]

Greetings fellow investors. 

So I have a question. I own a investment property that is valued at around 800k. I own it free and clear and I'm thinking of selling it. 

I was reading online that if you make under $47,025 you do not pay capital gains. I'm trying to figure out if its 47k is after i've deducted all my deductions and losses or is it based on the gross?

Because I paid so little for the property I fear I will be hit with a huge tax bill. My dream would be to sell the property and use my available cash to live on for the year so I stay under the 47k and use the money from the sale on a new rental and flip project. The projects would not be put on the market to rent and sell until Jan 2025.  

Does this sound crazy? if it does than feel free to mock me.